Let-off mechanism for looms



July 30, 1929. o. v. PAYNE LET-VOFF MECHANISM FOR LOOMS July 30, 1929. 0, v pAYNg 1,722,856

LET-OFF MECHANISM FOR LOOMS Filed Dec. 12, 1927 3 Sheets-Sheet 2 July 30, 1929. o. v. PAYNE 1,722,356

LET-OFF MECHANISM FOR LOOMS Filed Dec. 12, 1927 5 Sheets-Sheet 3 I [We/ for 1'7 0%0 yffiy/ze In "L V 46 III 6'! Mg 6 ISO Patented July 30, 1929 UNITED ,Frrc.

OSCAR v. PAYNE, or WORCESTER, MASSACHUSETTS, ASSIGNOR To CROMPTON & KNOWLES LOOM wORKS, or WORCESTER, MASSACHUSETTS, A CORPORATION OF MASSACHUSETTS.

LET-OFF MEGHANISM FOR LOOMS.

Application filed December 12, 1927. Serial No. 239,343.

This invention relates to mechanism' for letting oif warp in a loom during the proccss of weaving, and relates more particularly to the general type of let-off mechanism shown and described in my prior Patent No. 1,643,417, issued September 27, 1927 previously patented and to improve the letoff in many important features of construction.

My invention further relates to arrangements and combinations of parts which Wlll be hereinafter described and more particularly pointed out in the appended claims.

A preferred form of the invention is shown in the drawings in which Fig. 1 is a side elevation of portions of a loom embodying my improvements;

Fig. 2 is a partial sectional rear elevation, taken substantially along the line 2-2 1n Fig. 1; V r

Fig. 3 is a detail sectional plan view, taken along the line'3-3 in F g. 1;

Fig. 4 is a detail plan v1ew, looklng 1n the y direction of the arrow 4 in Fig. 1;

Fig. 5 is a detail sectional front elevation, taken along the line 5-5 in Fig. 1;

Fig. 6 is a detail side elevation, looking 1n the direction of the arrow 6 in Fig. 5;

Fig. 7 is a sectional rear elevation, taken along the line 7-7 in Fig. 6;

Fig. 8 is a view similar to Fig. but showing the parts in a different posltion;

Fig. 9 is a detail sectional plan view, taken along the line 9-9 in Fig. 5;

Fig. 10 is an enlarged side elevation of certain parts;

Fig. 11 is a detail sectional front elevation, takenalongthe line 1111 in Fig. 10;

Fig. 12 is a view similar to Fig. 10 but showing the parts in a different position;

Fig. 13 is a detail sectional plan view, taken along the line 1313 in Fig. 12;

Fig. 14 is a detail sectional front elevation, taken along the line 1414 in Fig. 1; Fig. 15 is a detail sectional plan view, looking in the direction of the arrow 15 in and from the warp beam 25 at the rear of the 100m past the lease rods 26 and through the harnesses 27 and reed 28 to the breast beam 29 and to suitable take up mechanism, not shown.

My improvements relate particularly to the mechanlsm provided for controlling the let-off of warp from the warp beam 25. A beam shaft 30 (Fig. 2) extends from the warp beam 25 through a bearing bracket 31 and is provided with a worm wheel 32. secured to i the outer end thereof. Similar bearlng brackets 31 areprovided at each end of the warp beam, said bearing brackets being ad ustable vertically byrods 33 (Figs. 1 and 16), threaded in lugs on said bearing bracketsv and rotatably mounted in stands 34 forming part of the associated stand 34 .(Fig. 16) and may be clamped thereto in adjusted position by bolts 36, the heads of which are received in T-shaped slots 37 in the stands 34. Hand wheels 38 are secured to the upper. ends of thethreaded rods 33 and by use of said hand wheelsthe warp beam 25 may be adjusted at any desired elevation.

The worm wheel 32 is engaged by a worm 40 (Figs. 1 and 10) mounted on a short shaft 41 rotatable in bearings42and 43 formed integral with or secured 'to' the bearing bracket 31 previously described. A lever 44 (Fig. 10) is pivoted on. a stud 45 and engages the lower or rear end of the shaft 41, applyingupward and forward pressure thereto.

The lower end. 46 of the lever 44 projects forward and is widened and recessed to provide sidebeari'ng portions 47 (Fig. 13) for rolls 48 on a stud 49 fixed in the forward end of a link 50. A third roll 51 on the stud 49 engages the ribbed lower face 52 of a tension lever 53 (Fig. 12) pivoted at 54 53, rolls 51 and 48, lever 44 and shaft 41,

tend to slide the worm 40 bodily forward and upward asviewed in Fig..'10, turning the warp beam 25 rearward and thus placing tension on the warp.

Therear end of the link 50 (Fig. 13) is pivoted at 57 to the lower end of a compensating lever 58, mounted on a short shaft 59 (Fig. 2), supported in bearings in a stand 60 which in turn is secured to the bearing bracket 31 previously described. A forked arm 61 is'secured'to the end of the shaft 59 and supports a presser roll 02, which preferably covered with cloth or other soft material and presses against the rear surface of the warp beam 25. A coil spring (33 applies tension to swing the presser roll 62 against the warp beam. The tension of the spring may be adjusted by turning a notched collar 64 on theshaft 59.

As the diameter of the warp beam 25 is reduced, the roll 62 and arm 61 swing forward, and the link 5() and rolls 48 and 51 are drawn rearward, as viewed in Figs. 10 and 11,'d'ecreasing the effective leverage be'- tween the weights 56 and the worm 40 and thus decreasing the tension applied to the worm wheel 32 to correspond to the reduced diameter of the warp beam 25.

It is frequently desirable to adjust the warp beam manually, and for this purpose Iprovide a hand wheel (Fig. 1) mounted on the frontend of an adjusting rod or shaft 71, slidable and rotatable in a bearing sleeve 72 pivotally mounted in a bracket 78 (Fig.

4) which in turn is pivoted in a fixed bear- .ing on the loom frame 20. At i-ts rear end 'the rod 71 is connected by a universal coupling 74 to the front end of the short Worm shaft 41. The worm shaft and worm may thus be rotated to adjust the warp beam in whatever vertical position it may occupy, and automatic axial or angular movement of the worm shaft is not interfered with.

- Feeding mechanism.

I will now describe the apparatus and connection through which the warp beam is rotated to let off the warp and by which the feed is adjusted in accordance with the --de1nands of the loom.

A ratchet wheel 75 (Fig. 6) is fixed on the front end of the worm shaft 41 and is engaged by, a feed pawl 7 6 (Fig- 7) pivoted at 77 at the upper end of. a feed lever 78, loosely mounted on the worm shaft 41. At

its lowerend the feed lever 78 is connected by a link 80 (Fig. 9) to an arm 81 (Fig. 15) having its hub. pivot-ed in alug 82 (Fig. 14) projecting laterally from the bearing bracket 31. The arm hub is held therein by a collar 83. A square rod or shaft 84 extends freely through the hub of the arm 81 but isnonrotatable relative thereto. Q

At its lower end, the rod 84 3) is supported in a suitable fixed bearing 85 and is provided with an arm 86 connected by a link 87' (Fig. 1) to an arm 88, fixed on the rock shaft 23 which supports the oscillating lay 21. As the lay swingsbaek and forth, the square shaft 84 is oscillated and acts through the arm 81, link 80 and feed lever 78 to oscillate the feed pawl 76 about the axis of the worm shaft 41.

The special construction of the link 80 permits the link 81 and arm 78 to swing in different planes and is best shown in Fig. 9.

A stud 90' is mounted in the end of the arm 7 8 and is provided with an enlarged. head or ball 91, received within a sleeve or tube 92 between a block 93 fixed in the end of the tube and a sliding block 94. A similar headed stud 95.is fixed. in the lower end of the feed lever 81 andis positioned. within the tube 92, between a block 96 fixed in the end of the tube and a sliding block 97 A coil spring 98 forces the two slidingblocks94 and 97 apart and causes them to yieldingly engage the heads of the studs 90 and 95,

thus forming a universal connectionbetween V the arm 81 and the lever 7 8.

a The feed pawl 7 6 7 is provided with a hardened plate 100 engaging the ratchet wheel 75,. and the feed pawl also has a rearwardly extending portion 101 engaged by a spring 102, causing the feed pawl to be moved yield'ingly toward the ratchet wheel. An offset projecting portion 103 of the feed pawl 76. restson the outer cam surface of a cam member 105 mounted in fixed-position on the bearing 42 10) of the worm shaft 41. The cam surface of the member 105 is inclined to: the axis of the worm shaft 41, as clearly shown in Fig. 6. d

When the lu-g108 of the feed pa-wl is when the worm'40 is moved downward and rearward by increased warp tension, 1 thus raising the weight 56 the feed. pawl will be moved to the left in Fig. 6, allowing earlier 7 engagement of the feed pawl with the ratchet wheel and consequently increasing the movement of the worm 40 and worm Wheel 32,. thus letting off more warp. As more warp is let off, the weights 56 will descend, moving the worm 40 forward and. upward and moving the feed pawl to- :theright in Fig; 6, thus reducing the feed and letting off warp more slowly. In this way the. rate of feed is controlled by the axial. position of the worm 40, which in turn is controlledzby the tension of the warp W and the feed is progressively and uniformly varied, instead of being merely interrupted as in my patented structure.

The weights 56 are selected to provide a desired tension with a given diameter of warp beam, and the presser roll 62 thereafter draws the rolls 48 and 51 (Fig. 13) rearward, varying the efiective action of the lever system and causing the weights 56 to maintain substantially uniform tension on the warp as the diameter of the warp beam is gradually reduced.

Having thus described my invention and the advantages thereof, I do not wish to be limited to the details herein disclosed otherwise than as set forth in the claims, but

what I claim is l. In a loom, a warp beam, a worm wheel thereon, a worm engaging said worm wheel, said worm being movable axially to tension the warp, a weight, a plurality of levers connecting said weight to apply axial pressure to said worm, and means to change the relative effective lengths of said levers in accordance with changes in warp beam diameter, thereby decreasing the application of axial pressure to said worm in accordance with the reduction in warp beam diameter.

2. In a loom, a warp beam, a worm wheel thereon, a worm engaging said worm wheel,

said worm being movable axially to tension the warp, means to apply axial pressure to said worm, and means to vary the application of axial pressure to said worm in accordance with the reduction in warp beam diameter, said tension applying means ineluding a pair of reversely extending levers and a pressure transmitting element positioned between said levers, and said pressure varying means including a warp beam engaging member effective to move said transmitting element longitudinally of said levers as the warp beam diameter is reduced.

said worm, and means to vary the a.pplication of axial pressure to said worm in accordance with the reduction in warp beam diameter, said tension applying means including a worm positioning lever having a forwardly extending portion, a weight lever extending rearwardly above said portion of said positioning lever, said weight lever and said positioning lever having adjacent and substantially parallel faces, and rolls between said faces effective to trans mit pressure from one lever to the other, and said pressure varying means acting to move said rolls rearward as the warp beam diameter decreases. I

42 In a loom, a warp beam, a worm wheel mounted thereon, a worm engaging said worm wheel, a worm shaft on which said worm is mounted, said worm and worm shaft being movable axially to tension the warp, a ratchet and feed pawl movable axially with said worm shaft, means to give said pawl a uniform feeding stroke and a fixed shield member directly engaging said feed pawl and having a cam action effective to vary the point of engagement of said pawl and ratchet in accordance with the axial position of said worm shaft.

5. The combination in a loom as set forth in claim 4, in which said shield member has a raised cam portion, with the pawl-engaging edge thereof inclined to the axis of said worm shaft,and in which said feed pawl has a portion engaging said raised portion and thereby rendering said feed pawl inoperative.

In testimony whereof I have hereunto affixed my signature.

OSCAR V. PAYNE. 

